/*
 * Copyright (C) 2009 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

package org.odk.aggregate;

import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;

/**
 * Entity Manager Factory singleton to prevent unnecessary construction
 *
 * @author wbrunette@gmail.com
 */
public final class EMFactory {
  /**
   * Singleton of the entity manager factory
   */
  private static final EntityManagerFactory emfInstance =
    Persistence.createEntityManagerFactory("transactions-optional");

  /**
   * Private constructor 
   */
  private EMFactory() {
  }

  /**
   * Get the entity manager factory singleton instance
   * 
   * @return
   *    entity manager factory instance
   */
  public static EntityManagerFactory get() {
    return emfInstance;
  }
}